ONS coding system explained

The ONS coding system was a hierarchical code used in the United Kingdom for tabulating census and other statistical data. ONS refers to the Office for National Statistics.

It was replaced by the GSS coding system on 1 January 2011.

Code formulation

Principal authorities

The code was constructed top down from a four character code representing a unitary authority or two-tier county and district.

or
00EC	Middlesbrough (unitary)
12	Cambridgeshire county
12UB	Cambridge district

Electoral wards and output areas

Local government wards had a two-letter code within their local authority, and census output area an additional four digits within a ward.

12UB	Cambridge district
12UBGA	Petersfield ward
12UBGA0001	Output area: Gwydir Street (north of junction with Hooper St)

The authority and ward codes were recognised by Eurostat as local administrative unit code levels 1 and 2 within the NUTS system.

Civil parishes

An overlapping system encoded civil parish areas. Parishes were represented by an additional three digits within their local authority:

12UD	Fenland district
12UD010	Tydd St. Giles parish

List of codes for counties and districts

The codes for counties and districts were as follows.^[1]

Also showing NUTS(3) codes thus: (UKH12)

Greater London

These codes became active following local government changes in 1986.

00AA (UKI11) City of London
00AB (UKI21) Barking and Dagenham
00AC (UKI23) Barnet
00AD (UKI21) Bexley
00AE (UKI23) Brent
00AF (UKI22) Bromley
00AG (UKI11) Camden
00AH (UKI22) Croydon
00AJ (UKI23) Ealing
00AK (UKI21) Enfield
00AL (UKI21) Greenwich
00AM (UKI12) Hackney
00AN (UKI11) Hammersmith and Fulham
00AP (UKI12) Haringey
00AQ (UKI23) Harrow
00AR (UKI21) Havering
00AS (UKI23) Hillingdon
00AT (UKI23) Hounslow
00AU (UKI12) Islington
00AW (UKI11) Kensington and Chelsea
00AX (UKI22) Kingston upon Thames
00AY (UKI12) Lambeth
00AZ (UKI12) Lewisham
00BA (UKI22) Merton
00BB (UKI12) Newham
00BC (UKI21) Redbridge
00BD (UKI23) Richmond upon Thames
00BE (UKI12) Southwark
00BF (UKI22) Sutton
00BG (UKI12) Tower Hamlets
00BH (UKI21) Waltham Forest
00BJ (UKI11) Wandsworth
00BK (UKI11) Westminster

Metropolitan counties

These codes became active following local government changes in 1986.

Greater Manchester districts
- 00BL (UKD32) Bolton
- 00BM (UKD32) Bury
- 00BN (UKD31) Manchester
- 00BP (UKD32) Oldham
- 00BQ (UKD32) Rochdale
- 00BR (UKD31) Salford
- 00BS (UKD31) Stockport
- 00BT (UKD31) Tameside
- 00BU (UKD31) Trafford
- 00BW (UKD32) Wigan
Merseyside districts
- 00BX (UKD51) Knowsley
- 00BY (UKD52) Liverpool
- 00BZ (UKD51) St Helens
- 00CA (UKD53) Sefton
- 00CB (UKD54) Wirral
South Yorkshire districts
- 00CC (UKE31) Barnsley
- 00CE (UKE31) Doncaster
- 00CF (UKE31) Rotherham
- 00CG (UKE32) Sheffield
Tyne and Wear districts
- 00CH (UKC22) Gateshead
- 00CJ (UKC22) Newcastle-upon-Tyne
- 00CK (UKC22) North Tyneside
- 00CL (UKC22) South Tyneside
- 00CM (UKC23) Sunderland
West Midlands districts
- 00CN (UKG31) Birmingham
- 00CQ (UKG33) Coventry
- 00CR (UKG34) Dudley
- 00CS (UKG34) Sandwell
- 00CT (UKG32) Solihull
- 00CU (UKG35) Walsall
- 00CW (UKG35) Wolverhampton
West Yorkshire districts
- 00CX (UKE41) Bradford
- 00CY (UKE43) Calderdale
- 00CZ (UKE43) Kirklees
- 00DA (UKE42) Leeds
- 00DB (UKE43) Wakefield

Non-hierarchical codes for Greater London and metropolitan counties

Unitary authorities established in the 1990s

These codes became active following local government changes the 1990s.

North East England region
- 00EB (UKC11) Hartlepool
- 00EC (UKC12) Middlesbrough
- 00EE (UKC12) Redcar and Cleveland
- 00EF (UKC11) Stockton-on-Tees
- 00EH (UKC13) Darlington
North West England region
- 00ET (UKD21) Halton
- 00EU (UKD21) Warrington
- 00EX (UKD41) Blackburn with Darwen
- 00EY (UKD42) Blackpool
Yorkshire and the Humber region
- 00FA (UKE11) Kingston upon Hull
- 00FB (UKE12) East Riding of Yorkshire
- 00FC (UKE13) North East Lincolnshire
- 00FD (UKE13) North Lincolnshire
- 00FF (UKE21) York
East Midlands region
- 00FK (UKF11) Derby
- 00FN (UKF21) Leicester
- 00FP (UKF22) Rutland
- 00FY (UKF14) Nottingham
West Midlands region
- 00GA (UKG11) Herefordshire
- 00GF (UKG21) Telford and Wrekin
- 00GL (UKG23) Stoke-on-Trent
South West England region
- 00HA (UKK12) Bath and North East Somerset
- 00HB (UKK11) Bristol
- 00HC (UKK12) North Somerset
- 00HD (UKK12) South Gloucestershire
- 00HG (UKK41) Plymouth
- 00HH (UKK42) Torbay
- 00HN (UKK21) Bournemouth
- 00HP (UKK21) Poole
- 00HX (UKK14) Swindon
East of England region
- 00JA (UKH11) Peterborough
- 00KA (UKH21) Luton
- 00KF (UKH31) Southend-on-Sea
- 00KG (UKH32) Thurrock
South East England region
- 00LC (UKJ41) Medway
- 00MA (UKJ11) Bracknell Forest
- 00MB (UKJ11) West Berkshire
- 00MC (UKJ11) Reading
- 00MD (UKJ11) Slough
- 00ME (UKJ11) Windsor and Maidenhead
- 00MF (UKJ11) Wokingham
- 00MG (UKJ12) Milton Keynes
- 00ML (UKJ21) Brighton and Hove
- 00MR (UKJ31) Portsmouth
- 00MS (UKJ32) Southampton
- 00MW (UKJ34) Isle of Wight

Unitary authorities established in 2009

These codes became active following local government changes in 2009.

00KB Bedford
00KC Central Bedfordshire
00EQ Cheshire East
00EW Cheshire West and Chester
00HE Cornwall
00HF Isles of Scilly
00EJ County Durham
00EM Northumberland
00GG Shropshire
00HY Wiltshire

Non-metropolitan counties

08 Avon
- 08UB Bath
- 08UC Bristol
- 08UD Kingswood
- 08UE Northavon
- 08UF Wansdyke
- 08UG Woodspring
09 (UKH22) Bedfordshire
- 09UB Luton
- 09UC Mid Bedfordshire
- 09UD Bedford
- 09UE South Bedfordshire
10 Berkshire
- 10UB Bracknell Forest
- 10UC Newbury
- 10UD Reading
- 10UE Slough
- 10UF Windsor and Maidenhead
- 10UG Wokingham
11 (UKJ13) Buckinghamshire
- 11UB Aylesbury Vale
- 11UC Chiltern
- 11UD Milton Keynes
- 11UE South Bucks
- 11UF Wycombe
12 (UKH12) Cambridgeshire
- 12UB Cambridge
- 12UC East Cambridgeshire
- 12UD Fenland
- 12UE Huntingdonshire
- 12UF Peterborough
- 12UG South Cambridgeshire
13 (UKD22) Cheshire
- 13UB Chester
- 13UC Congleton
- 13UD Crewe and Nantwich
- 13UE Ellesmere Port and Neston
- 13UF Halton
- 13UG Macclesfield
- 13UH Vale Royal
- 13UJ Warrington
14 Cleveland
- 14UB Hartlepool
- 14UC Langbaurgh-on-Tees
- 14UD Middlesbrough
- 14UE Stockton-on-Tees
15 (UKK30) Cornwall and Scilly
- 15UB Caradon
- 15UC Carrick
- 15UD Kerrier
- 15UE North Cornwall
- 15UF Penwith
- 15UG Restormel
- 15UH Isles of Scilly
16 Cumbria
- 16UB (UKD11) Allerdale
- 16UC (UKD11) Barrow-in-Furness
- 16UD (UKD12) Carlisle
- 16UE (UKD11) Copeland
- 16UF (UKD12) Eden
- 16UG (UKD12) South Lakeland
17 Derbyshire
- 17UB (UKF13) Amber Valley
- 17UC (UKF12) Bolsover
- 17UD (UKF12) Chesterfield
- 17UE Derby
- 17UF (UKF13) Derbyshire Dales
- 17UG (UKF13) Erewash
- 17UH (UKF13) High Peak
- 17UJ (UKF12) North East Derbyshire
- 17UK (UKF13) South Derbyshire
18 (UKK43) Devon
- 18UB East Devon
- 18UC Exeter
- 18UD Mid Devon
- 18UE North Devon
- 19UF Plymouth
- 18UG South Hams
- 18UH Teignbridge
- 19UJ Torbay
- 18UK Torridge
- 18UL West Devon
19 (UKK22) Dorset
- 19UB Bournemouth
- 19UC Christchurch
- 19UD East Dorset
- 19UE North Dorset
- 19UF Poole
- 19UG Purbeck
- 19UH West Dorset
- 19UJ Weymouth and Portland
20 (UKC14) County Durham
- 20UB Chester-le-Street
- 20UC Darlington
- 20UD Derwentside
- 20UE Durham
- 20UF Easington
- 20UG Sedgefield
- 20UH Teesdale
- 20UJ Wear Valley
21 (UKJ22) East Sussex
- 21UB Brighton
- 21UC Eastbourne
- 21UD Hastings
- 21UE Hove
- 21UF Lewes
- 21UG Rother
- 21UH Wealden
22 (UKH33) Essex
- 22UB Basildon
- 22UC Braintree
- 22UD Brentwood
- 22UE Castle Point
- 22UF Chelmsford
- 22UG Colchester
- 22UH Epping Forest
- 22UJ Harlow
- 22UK Maldon
- 22UL Rochford
- 22UM Southend-on-Sea
- 22UN Tendring
- 22UP Thurrock
- 22UQ Uttlesford
23 (UKK13) Gloucestershire
- 23UB Cheltenham
- 23UC Cotswold
- 23UD Forest of Dean
- 23UE Gloucester
- 23UF Stroud
- 23UG Tewkesbury
24 (UKJ33) Hampshire
- 24UB Basingstoke and Deane
- 24UC East Hampshire
- 24UD Eastleigh
- 24UE Fareham
- 24UF Gosport
- 24UG Hart
- 24UH Havant
- 24UJ New Forest
- 24UK Portsmouth
- 24UL Rushmoor
- 24UM Southampton
- 24UN Test Valley
- 24UP Winchester
25 Hereford and Worcester
- 25UB Bromsgrove
- 25UC Hereford
- 25UD Leominster
- 25UE Malvern Hills
- 25UF Redditch
- 25UG South Herefordshire
- 25UH Worcester
- 25UJ Wyre Forest
- 25UK Wychavon
26 (UKH23) Hertfordshire
- 26UB Broxbourne
- 26UC Dacorum
- 26UD East Hertfordshire
- 26UE Hertsmere
- 26UF North Hertfordshire
- 26UG St Albans
- 26UH Stevenage
- 26UJ Three Rivers
- 26UK Watford
- 26UL Welwyn Hatfield
27 Humberside
- 27UB Boothferry
- 27UC Cleethorpes
- 27UD East Yorkshire
- 27UE Beverley
- 27UF Glanford
- 27UG Holderness
- 27UH Great Grimsby
- 27UJ Kingston upon Hull
- 27UK Scunthorpe
28 Isle of Wight county
- 28UB Medina
- 28UC South Wight
29 (UKJ42) Kent
- 29UB Ashford
- 29UC Canterbury
- 29UD Dartford
- 29UE Dover
- 29UF Gillingham
- 29UG Gravesham
- 29UH Maidstone
- 29UJ Rochester upon Medway
- 29UK Sevenoaks
- 29UL Shepway
- 29UM Swale
- 29UN Thanet
- 29UP Tonbridge and Malling
- 29UQ Tunbridge Wells
30 (UKD43) Lancashire
- 30UB Blackburn
- 30UC Blackpool
- 30UD Burnley
- 30UE Chorley
- 30UF Fylde
- 30UG Hyndburn
- 30UH Lancaster
- 30UJ Pendle
- 30UK Preston
- 30UL Ribble Valley
- 30UM Rossendale
- 30UN South Ribble
- 30UP West Lancashire
- 30UQ Wyre
31 (UKF22) Leicestershire
- 31UB Blaby
- 31UC Charnwood
- 31UD Harborough
- 31UE Hinckley and Bosworth
- 31UF Leicester
- 31UG Melton
- 31UH North West Leicestershire
- 31UJ Oadby and Wigston
- 31UK Rutland
32 (UKF30) Lincolnshire
- 32UB Boston
- 32UC East Lindsey
- 32UD Lincoln
- 32UE North Kesteven
- 32UF South Holland
- 32UG South Kesteven
- 32UH West Lindsey
33 (UKH13) Norfolk
- 33UB Breckland
- 33UC Broadland
- 33UD Great Yarmouth
- 33UE King's Lynn and West Norfolk
- 33UF North Norfolk
- 33UG Norwich
- 33UH South Norfolk
34 (UKF23) Northamptonshire
- 34UB Corby
- 34UC Daventry
- 34UD East Northamptonshire
- 34UE Kettering
- 34UF Northampton
- 34UG South Northamptonshire
- 34UH Wellingborough
35 (UKC21) Northumberland
- 35UB Alnwick
- 35UC Berwick-upon-Tweed
- 35UD Blyth Valley
- 35UE Castle Morpeth
- 35UF Tynedale
- 35UG Wansbeck
36 (UKE22) North Yorkshire
- 36UB Craven
- 36UC Hambleton
- 36UD Harrogate
- 36UE Richmondshire
- 36UF Ryedale
- 36UG Scarborough
- 36UH Selby
- 36UJ York
37 Nottinghamshire
- 37UB (UKF15) Ashfield
- 37UC (UKF15) Bassetlaw
- 37UD (UKF16) Broxtowe
- 37UE (UKF16) Gedling
- 37UF (UKF15) Mansfield
- 37UG (UKF15) Newark and Sherwood
- 37UH Nottingham
- 37UJ (UKF16) Rushcliffe
38 (UKJ14) Oxfordshire
- 38UB Cherwell
- 38UC Oxford
- 38UD South Oxfordshire
- 38UE Vale of White Horse
- 38UF West Oxfordshire
39 (UKG22) Shropshire
- 39UB Bridgnorth
- 39UC North Shropshire
- 39UD Oswestry
- 39UE Shrewsbury and Atcham
- 39UF South Shropshire
- 39UG The Wrekin
40 (UKK23) Somerset
- 40UB Mendip
- 40UC Sedgemoor
- 40UD South Somerset
- 40UE Taunton Deane
- 40UF West Somerset
41 (UKG24) Staffordshire
- 41UB Cannock Chase
- 41UC East Staffordshire
- 41UD Lichfield
- 41UE Newcastle-under-Lyme
- 41UF South Staffordshire
- 41UG Stafford
- 41UH Staffordshire Moorlands
- 41UJ Stoke-on-Trent
- 41UK Tamworth
42 (UKH14) Suffolk
- 42UB Babergh
- 42UC Forest Heath
- 42UD Ipswich
- 42UE Mid Suffolk
- 42UF St. Edmundsbury
- 42UG Suffolk Coastal
- 42UH Waveney
43 (UKJ23) Surrey
- 43UB Elmbridge
- 43UC Epsom and Ewell
- 43UD Guildford
- 43UE Mole Valley
- 43UF Reigate and Banstead
- 43UG Runnymede
- 43UH Spelthorne
- 43UJ Surrey Heath
- 43UK Tandridge
- 43UL Waverley
- 43UM Woking
44 (UKG13) Warwickshire
- 44UB North Warwickshire
- 44UC Nuneaton and Bedworth
- 44UD Rugby
- 44UE Stratford-on-Avon
- 44UF Warwick
45 (UKJ24) West Sussex
- 45UB Adur
- 45UC Arun
- 45UD Chichester
- 45UE Crawley
- 45UF Horsham
- 45UG Mid Sussex
- 45UH Worthing
46 (UKK15) Wiltshire
- 46UB Kennet
- 46UC North Wiltshire
- 46UD Salisbury
- 46UE Thamesdown
- 46UF West Wiltshire
47 (UKG12) Worcestershire
- 47UB Bromsgrove
- 47UC Malvern Hills
- 47UD Redditch
- 47UE Worcester
- 47UF Wychavon
- 47UG Wyre Forest

Wales

These codes became active following local government changes in 1996.

00NA (UKL11) Isle of Anglesey
00NC (UKL12) Gwynedd
00NE (UKL13) Conwy
00NG (UKL13) Denbighshire
00NJ (UKL23) Flintshire
00NL (UKL23) Wrexham
00NN (UKL24) Powys
00NQ (UKL14) Ceredigion
00NS (UKL14) Pembrokeshire
00NU (UKL14) Carmarthenshire
00NX (UKL18) Swansea
00NZ (UKL17) Neath Port Talbot
00PB (UKL17) Bridgend
00PD (UKL22) Vale of Glamorgan
00PF (UKL15) Rhondda Cynon Taff
00PH (UKL15) Merthyr Tydfil
00PK (UKL16) Caerphilly
00PL (UKL16) Blaenau Gwent
00PM (UKL16) Torfaen
00PP (UKL21) Monmouthshire
00PR (UKL21) Newport
00PT (UKL22) Cardiff

Scotland

These codes became active following local government changes in 1996.

00QA (UKM10) Aberdeen
00QB (UKM10) Aberdeenshire
00QC (UKM21) Angus
00QD (UKM31/43) Argyll and Bute
00QE (UKM24) Scottish Borders
00QF (UKM22) Clackmannanshire
00QG (UKM31) West Dunbartonshire
00QH (UKM32) Dumfries and Galloway
00QJ (UKM21) Dundee
00QK (UKM33) East Ayrshire
00QL (UKM31) East Dunbartonshire
00QM (UKM23) East Lothian
00QN (UKM35) East Renfrewshire
00QP (UKM25) Edinburgh
00QQ (UKM26) Falkirk
00QR (UKM22) Fife
00QS (UKM34) Glasgow
00QT (UKM41/42/43) Highland
00QU (UKM35) Inverclyde
00QW (UKM23) Midlothian
00QX (UKM10/42) Moray
00QY (UKM33/43) North Ayrshire
00QZ (UKM36) North Lanarkshire
00RA (UKM45) Orkney Islands
00RB (UKM27) Perth and Kinross
00RC (UKM35) Renfrewshire
00RD (UKM46) Shetland Islands
00RE (UKM37) South Ayrshire
00RF (UKM38) South Lanarkshire
00RG (UKM27) Stirling
00RH (UKM28) West Lothian
00RJ (UKM44) Eilean Siar (Western Isles)

Northern Ireland

95A (UKN04) Derry
95B (UKN04) Limavady
95C (UKN04) Coleraine
95D (UKN04) Ballymoney
95E (UKN04) Moyle
95F (UKN03) Larne
95G (UKN03) Ballymena
95H (UKN05) Magherafelt
95I (UKN05) Cookstown
95J (UKN04) Strabane
95K (UKN05) Omagh
95L (UKN05) Fermanagh
95M (UKN05) Dungannon and South Tyrone
95N (UKN03) Craigavon
95O (UKN05) Armagh
95P (UKN05) Newry and Mourne
95Q (UKN03) Banbridge
95R (UKN03) Down
95S (UKN02) Lisburn
95T (UKN03) Antrim
95U (UKN02) Newtownabbey
95V (UKN02) Carrickfergus
95W (UKN02) North Down
95X (UKN03) Ards
95Y (UKN02) Castlereagh
95Z (UKN01) Belfast

External links

ONS Beginners' Guide to UK Geography

Notes and References

Web site: District Names and Codes for England and Wales as at 31/12/1994 . statistics.gov.uk . 4 November 2023 . https://web.archive.org/web/20110604135516/http://www.statistics.gov.uk/geography/downloads/02_11_01_District_names_and_codes_E_W_12_94.xls . 4 June 2011.